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Infantile Malignant Osteopetrosis Resources

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Infantile Malignant Osteopetrosis is a severe bone disorder that affects children and prevents normal bone growth; the bone deficiencies cause bone marrow failure, vision and hearing loss, and other complications and frequently result in death during the early years of life.

FAQs about Rocket’s Gene Therapy Approach to IMO

IMO is a rare, inherited disorder characterized by deficient osteoclast development and/or function, resulting in defective bone resorption and growth. Symptoms manifest soon after birth or in early infancy. IMO is caused by a mutation in the TCIRG1 gene, which is important for the process of bone resorption. It is often lethal, and unless treated, patients will die within the first decade of their life due to bone marrow failure, secondary infections or other complications.

Blood stem cells are first collected from a patient.  These stem cells are then genetically modified in a laboratory to introduce a correct copy of the TCIRG1 gene using a virus that has been changed so that the virus cannot grow, spread, or cause an infection. The patient is then given a type of chemotherapy medication called busulfan to remove existing bone marrow cells to make room for the genetically modified stem cells (this is also known as conditioning therapy). After receiving busulfan, the patient is given an intravenous infusion of the genetically modified blood stem cells, similar to having a transfusion.

Patients who:

  • Have an IMO diagnosis with a confirmed TCIRG1 mutation
  • Are at least 1 month old with minimum weight of 4 kg
  • Do not have debilitating hydrocephalus
  • Have a Lansky Play Scale of at least 60%
  • Have no medical conditions that would prevent autologous hematopoietic stem cell transplant
  • Have absolute neutrophil count above 500/mm3 and platelet count above 25,000/mm3
  • Have no prior allogeneic or other hematopoietic stem cell transplant
  • Have back up hematopoietic stem cell donor/source

Before patients join the clinical trial, they will have to undergo several medical tests at the study center to determine whether they are eligible to join the trial. Following confirmation that a patient meets the eligibility criteria for the trial, participating in the clinical trial will involve:

  • Stem Cell Collection: 
    A patient will receive medications over several days to cause stem cells to enter the blood from the bone marrow. These stem cells have the potential to make different blood cells in the body for the remainder of a patient’s life. The stem cells will be collected from the body through a catheter temporarily placed in a vein. This procedure is called apheresis.  
  • Infusion of Genetically Modified Stem Cells (the Investigational Gene Therapy): 
    A patient’s stem cells will be genetically modified in a laboratory to introduce the correct copy of the TCIRG1. Before receiving the new cells, the patient will receive a chemotherapy medication called busulfan to remove the existing bone marrow cells to make room for the genetically modified cells. The patient will then receive an intravenous infusion of the genetically modified cells through the catheter, similar to having a transfusion. 
  • Follow-up after Administration of the Investigational Gene Therapy: 
    Patients will need to return for follow-up visits, including blood and bone marrow tests, over the next 2 years.  In addition, patients may expect to have long-term follow-ups with their home physician approximately 1-2 times per year for another 13 years.
  • University of California, Los Angeles (UCLA), California, USA

Financial support, including travel arrangements and housing accommodations for patients and a family member, both for the treatment and follow-up visits, will be provided.  This will also include assistance with passports, medical visas and translation services for patients and families if these are needed.

If your group would like to be included in our list of patient resources, please reach out to us at [email address].

For additional resources, we encourage you to reach out to the groups below.

If your group would like to be included in our list of patient resources, please reach out to us at patients@nullrocketpharma.com.

IMO is a rare, inherited disorder characterized by deficient osteoclast development and/or function, resulting in defective bone resorption and growth. Symptoms manifest soon after birth or in early infancy. IMO is caused by a mutation in the TCIRG1 gene, which is important for the process of bone resorption. It is often lethal, and unless treated, patients will die within the first decade of their life due to bone marrow failure, secondary infections or other complications.

Blood stem cells are first collected from a patient.  These stem cells are then genetically modified in a laboratory to introduce a correct copy of the TCIRG1 gene using a virus that has been changed so that the virus cannot grow, spread, or cause an infection. The patient is then given a type of chemotherapy medication called busulfan to remove existing bone marrow cells to make room for the gene-modified stem cells (this is also known as conditioning therapy). After receiving busulfan, the patient is given an intravenous infusion of the gene-modified blood stem cells, similar to having a transfusion.

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